Take-up for intermittently fed strips or sheets



Dec'.s,1942.- J.'STAM' 2,304,213

TAKE-UP FOR AN INTERMITTENTLY FED STRIP OR SHEET Filed Aug. 19) 1939 2 Sheets-Sheet 1 Java wife a":

(766556 Siam; I m, 7%, MM PM-(B12296 Patented Dec. 8, 1942 TAKE-UP. FOR INTERMITTENTLY FED STRIPS on SHEETS Jesse 'Stam, Newton' Center, Mass.

1 Application August 19, 1939,.Serial No. 291,038

Claims. (01. 242-55) This invention relates 'to a take-up for an intermittently fed strip or sheet, and is particularly useful in connection with a sewing machine in which the feeding of the material occurs only "when the needle is withdrawn from the fabric, although it may be employed in other analogous situations. The nature of the take-up is such thatit utilizes stoppage of the material to nullify the effect of the take-up.

The invention will best be understood by reference to the following description when taken in connection with the accompanying drawings of one specific embodiment thereof, while its scope will be pointed out more particularly in the appended claims.

In the drawings:

Figure 1 is a front elevation of a take-up embodying the invention;

Fig. 2 is an elevation viewed from the left side of Fig. 1, the strip-winding drum being omitted; and

Fig. 3 is a sectional view on an enlarged scale on line 3-3 of Fig. 2.

Referring to the drawings and to the embodiment of the invention illustrated therein by way of example, there is shown a take-up comprising a take-up member, herein a strip-winding drum or spool 4 fixedly secured to a shaft 6 rotatably supported in bearings 8 presented by a frame 10. Power is furnished to the drum through appropriate driving mechanism including driving and driven members l2 and i4 having frictional driving engagement with each other, as by peripheral contact.

In the present example, the driving member I2 is a shaft mounted in bearings IS on the frame 10 and receiving power from an appropriate source. As shown, a pulley l8, fixedly secured to the shaft, serves to transmit power thereto. The driven member I4 is conveniently in the form of a soft rubber tire having a favorable coefficient of friction, and it is freely movable toward and from the driving member 12 as by being mounted on a wheel 20 fixedly secured to a shaft 22 mounted in vertically movable bearings 24, one of which is shown in detail in Fig. 3.

When, as in the present example, the arrangement is such that gravity may be relied upon to urge the driven member 14 against the driving member, gravity alone may suffice for this purpose, but I prefer to supplement gravity as by the use of springs 26, one of which is shown in Fig. 3, particularly because, as in the present example, springs lend themselves very nicely to an arrangement for varying the frictional pressure, as by adjustablespring loading screws 28,

one of which is. shown in Fig. 3,.threaded into one. of apair of guides: 30 for the vertically movable bearing 24. I

The driving mechanism also includes means, now .to be described, for utilizing stoppage of the rotation of the Winding drum 4to nullify the effect of the take-uptemporarily as bycausing a reduction of, if not-the complete removal of,

frictional pressureof .thedriven member [4 on the'driving member l2.

complished in the present example by a sprocket This .isconveniently. ac-

wheel 32 fixedly secured to the vertically movable shaft 22, a sprocket wheel 34 secured to the shaft 6, and a chain 36 connecting said sprocket wheels. This mechanism may, if desired, be in duplicate, one on either side of the member H, but I have found in practice that the single mechanism shown suffices very well as the vertical travel of the shaft 22 is slight and brief.

The driving mechanism just described has the peculiar property of causing the shaft 22 to ascend instantly when rotation of the upper sprocket wheel 34 is stopped briefly by stoppage of the feeding of the strip by the sewing machine. Conversely, when the feeding of the strip is resumed, the shaft 22 descends under the influence of gravity plus the effect of the springs 26. The action is continuous and automatic. The reason for this is apparent from an inspection of Fig. 2, from which it is apparent that when the left-hand lead of the chain cannot descend, the turning moment imparted by the driving shaft l2 to the sprocket wheel 32 causes the latter to ascend said lead instantly, though onlyslightly because the stoppage of the feeding of the strip by the sewing machine is very brief.

This action is exceedingly prompt and sensitive.

and is in perfect synchronism with the feeding and non-feeding intervals of the sewing machine. Adjustment of the loading of the springs 26 can be made so that, during the feeding periods of the sewing machine, the take-up will not interfere with the operation of the sewing machine.

There is, of course, another factor to be con-' sidered, and that is the increase of diameter of the strip wound on the take-up drum and the consequent increase in linear speed of the strip while at the same time the feed of the strip from the sewing machine remains constant. This means that the R. P. M. of the take-up drum is reduced gradually and this is taken care of by the necessarily increased slippage of the driving member l2 with relation to the driven member l4.

Having thus described one embodiment of the invention, but without limiting myself thereto, what I claim and desire, by Letters Patent, to secure is:

1. In a take-up mechanism for an intermittently fed strip, the combination of driving and driven members whose peripheries have frictional driving engagement with each other, said driven member resting upon said driving. member, a lower, driving, sprocket wheel =whichis free to move upwardly and carries said driven member vertically, an upper, driven, sprocket wheel, .a

strip winding drum driven by the last-mentioned wheel, and a chain connecting said rsprocket wheels and having a lead which said lower sprocket wheel ascends when said winding v drum ber to said shaft, saidgearing including two meshing members, onefreely movable bodily along the other-and carrying said driven, member with it when, said windingldrum stops.

3. Ina mechanism ;for.transmitting ,power to cause interruption ,of the application .of power thereto, thetcombinationof a driving member a body and toutilize stoppage of said bodylto ;30

to be connected to the power source, a driven member normally pressed against said driving member, and mechanism to utilize stoppage of the body to be driven to relieve the pressure of said driven member against said driving member.

4. In a mechanism for transmitting ower to a strip winding drum and to utilize stoppage of said drum to cause interruption of the application of power thereto, the combination of a driving member to be connectedto the power source, a driven member normally pressed against said driving member, and mechanism to utilize stoppage of the drum to be driven to relieve the pres- .sure of said driven member against said driving member, said mechanism including interengaging, power-transmitting members, one freely movable bodily along the other and carrying said driven member .with it when said drum stops.

5. The combination of a strip winding drum and mechanism for applying power to said drum inversely to the resistance of said strip winding drum, said mechanism including two frictionally engaging members, one movabletoward andifrom the other, and means to utilize increased resist- 'ance of said drum to rotation to cause diminished application ofpower thereto,-said means including two interengaging, power-transmitting members, one freely movable bodilyalong the other and carrying one of .said .frictionallyengaging members when said drum stops.

, JESSE STAM. 

